A 17-year-old male was taken to Cedars-Sinai Hospital in critical condition after being shot in the chest and leg, Chao said. A 25-year-old was also taken to Cedars-Sinai with a gunshot wound to his buttocks and 14-year-old was taken to USC Medical Center with an injury to his foot.

Hollywood was experiencing a mass exodus of Halloween revelers after the shooting closed off Hollywood Boulevard between Cahuenga Boulevard and Highland Avenue, Chao said. Freeway traffic in the area was also being affected.

Authorities were directing "several thousand" to clear the area in order to conduct a crime scene investigation.